Q: I'm a 37-year-old dad to two kids, recently remarried. Before I met my current wife I had no desire for more kids. I have 40 percent custody of the kids, and I love being a parent.

My wife would like us to have a child of our own, but is not desperate. My ex-wife, however, contends that it is purely selfish of me to want more kids and that if I was previously satisfied with the ones we have, then the issue isn't about kids, it's about wanting to validate my new marriage. I consider her a friend and she usually does not antagonize me about my marriage, so I don't know how to take this coming from her, or whether she's right. What do you think?

New Hampshire

A: I think her choice of the word "selfish" was unfortunate, because that bumped a valid concern into antagonism.

First, the valid concern. As their mother, your ex-wife is going to champion your kids, and calculate what your maybe-baby would mean for them: less of your money, less of your time, less of you. If you haven't thought of those three implications, then you need to think of them. She was right to.

Next, the valid counterargument. Where there's no scarcity of love, maturity, responsibility, generosity of spirit and (to a lesser extent) money, I could argue your having a child with your new wife wouldn't take you away from your kids so much as it would give them a sibling.

Whether half-siblings regard themselves as teammates or rivals is not entirely up to the parents, but parents set the tone. You can either be honest with yourself about what you can handle, or you can take on too much and leave everyone's needs unmet. You can love all your kids unselfishly, or you can play favorites. You can put your kids first, any kids you help(ed) create, with any mom — or you can prioritize a mom at the kids' expense. You can encourage factions, or you can make cooperation among all adults the centerpiece of what you do.

Now, the antagonism. As the mother of two, your wife knows you don't have a second child because the first one wasn't "satisfying." Maybe a great first child will lead to another, but surely she wouldn't suggest that people with one child quit while they were behind? Or quit because their one was perfect? Every branch of this reasoning line is ugly.

Family size comes down to who the parents are, how they live, and how much room they have in their hearts, minds, health, priorities, lifestyles and bank accounts. And if one or more of those list items changed when you got remarried, then it's not outrageous for the family size to change, too.

Meanwhile, when you remarried, you assumed your new wife's needs and desires as your own. Therefore, your willingness to consider her desire for a child isn't, couldn't be, "purely selfish." As a husband, a father, an ex-husband and as a man, you have a lot of people's needs and desires to weigh, and all of them count for something.

The question for you now is, where does each need appear on the list, and how far down that list can you responsibly, lovingly go?